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An Al Jazeera documentary has raised serious questions about official investigations into the safety of more than 1,500 of the most commonly-used passenger planes in the world.

Boeing's 737NG is flown by more than 150 airlines worldwide, but for more than 10 years whistleblowers who used to work for Boeing have raised serious doubts about the manufacture of key structural parts for many of the planes.

The parts in question are called "chords" and "bear straps": the chords make up the ribs of the aircraft fuselage and the bear straps are huge sheets which reinforce the exits and doorways on the fuselage.

The whistleblowers have made claims in a US court that the parts – made by a sub-contractor for Boeing between 1996 and 2004 - were ill-fitting and illegal, but that Boeing used many of them to build the aircraft.

Aviation experts working with these whistleblowers tell the programme that the problem with these parts could lead to a "catastrophic failure" of aircraft fitted with them.

Allegations dismissed

PEOPLE AND POWER
On a wing and a prayer

Boeing has dismissed the allegations as "without merit", and the American Federal Aviation Administration – which regulates the US aircraft industry - has supported Boeing.

But a year-long investigation by Al Jazeera's People & Power series has uncovered a draft internal Boeing memorandum which appears to contradict Boeing’s assertion and, instead, supports the whistleblowers’ allegations. 

The document warns that the problem highlighted by the whistleblowers "poses a quality risk to the production of quality airplane parts" and that the "integrity" of the sub-contractor places Boeing itself "at risk".

The programme has also found evidence which calls into question how thoroughly the FAA investigated the alleged problems. It reveals information contained in the files of another US federal agency – the Defence Criminal Investigative Service – which appears to support some of the whistleblowers’ claims.

The documentary features testimony by the whistleblowers, their lawyer and aviation safety experts working with them that the US government itself has covered up some of this evidence – and that it appears to be assisting Boeing in the federal court case.

On a Wing and a Prayer: a specially-extended episode of People & Power can be seen from from Wednesday, December 15, 1900GMT.

Source: Al Jazeera